Touch control equipment has become the preferred configuration of present man-machine interaction electronic products due to its features of simple and convenient operation, and can be found everywhere from industry to family, and from office to entertainment. For touch control equipment, people raise more expectations and requirements simultaneously when pursuing accuracy, stabilization and convenience, such as reducing price, reducing the energy consumption, further enhancing the sensitivity of touching energy and force, and etc.
Nowadays, there are many kinds of technique for measuring touching, including: resistive, capacitive, infrared-ray type, SAW type, electro-magnetic type, optical or near field imaging type and etc. These techniques for measuring touching are very sensitive to touching position, but they all have two drawbacks in common: 1. failing to detect the touching energy or force; 2. when touching sensing area increases, the cost of touching sensing system rises up dramatically. For the problem of failing to detect touching force, at present, many techniques use a sensor group distributed under the touch screen to solve this problem. But this manner has several big defects as follows: 1. the sensor can only detect nearby force thereof, therefore, more sensors are needed to form a sensor group to cover the entire touch screen, which will increase the weight, complexity and power consumption of the equipment; 2. the sensors and the fingers are also separated by several layers of glass; the touching energy of the fingers is dispersed and attenuated by layers of glass before detected by the sensors, therefore, the precision is not good,
For high-cost problem, there is no fine solution at present.